• Nuclear Engineering and Technology
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• 제37권3호
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• pp.245-258
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• 2005

This paper addresses two types of uncertainty: stochastic uncertainty and subjective uncertainty in probabilistic accident consequence assessments. The off-site consequence assessment code OSCAAR has been applied to uncertainty and sensitivity analyses on the individual risks of early fatality and latent cancer fatality in the population outside the plant boundary due to a severe accident. A new stratified meteorological sampling scheme was successfully implemented into the trajectory model for atmospheric dispersion and the statistical variability of the probability distributions of the consequence was examined. A total of 65 uncertain input parameters was considered and 128 runs of OSCAAR with 144 meteorological sequences were performed in the parameter uncertainty analysis. The study provided the range of uncertainty for the expected values of individual risks of early and latent cancer fatality close to the site. In the sensitivity analyses, the correlation/regression measures were useful for identifying those input parameters whose uncertainty makes an important contribution to the overall uncertainty for the consequence. This could provide valuable insights into areas for further research aiming at reducing the uncertainties.

• 한국사회정책
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• 제24권2호
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• pp.87-126
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• 2017

본 연구는 Rodgers(1989)가 제안한 불안정성의 세 가지 차원인 자원의 결핍, 불확실성, 통제권한의 부재를 이론적 분석 틀로 하여 한국 청년들이 경험하는 불안정성의 정도를 파악하고, 이들의 주관적 행복감에 영향을 미치는 요인들을 통합적으로 분석하는 것을 목적으로 하였다. 2010년에 실시된 제 8차 한국종합사회조사(Korean General Social Survey, KGSS) 자료를 활용하여 청년세대인 만 19세부터 만 34세의 총 415명을 분석대상으로 하였고, 이들이 인식하는 주관적 건강상태와 가구 소득수준, 사회적 지지라는 세 가지 자원의 결핍이 삶의 불확실성과 통제권한의 부재라는 불안정성의 요소들을 통해 행복에 미치는 경로모형을 구조방정식을 활용하여 분석하였다. 그리고 청년세대를 저연령 집단(만 19세-26세)과 고연령 집단(만 27세-34세)으로 구분하여 연령집단 별로 어떠한 차이가 나타나는지 다중집단분석을 실시하였다. 분석 결과, 자원의 결핍 및 불확실성과 통제권한의 부재 모두 청년들의 행복감에 직접적인 영향을 미쳤고, 그중에서 통제권한의 부재가 청년들의 행복에 가장 큰 영향을 미치는 것으로 나타났다. 또한 주관적 건강상태와 소득수준, 사회적 지지 모두 통제권한의 부재를 통해서만 행복에 간접적인 영향을 미쳤다. 그리고 다중집단분석 결과, 저연령 집단과 비교했을 때 고연령 집단에서만 소득수준이 행복에 유의한 영향을 미쳤고, 고연령 집단의 통제권한의 부재가 행복수준에 미치는 영향이 저연령 집단보다 컸다. 이러한 연구 결과를 바탕으로 정책 제언과 향후 연구 과제를 제시하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1158-1164
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• 2007

Recently, the demand on the practical application of life-cycle cost effectiveness for design and rehabilitation of civil infrastructure is rapidly growing unprecedentedly in civil engineering practice. Accordingly, it is expected that the life-cycle cost in the 21st century will become a new paradigm for all engineering decision problems in practice. However, in spite of impressive progress in the researches on the LCC, so far, most researches in Koreahave only focused on roadway bridges, which are not applicable to railway bridges. Thus, this paper presents the formulation models and methods for uncertainty-based LCCA for railroad bridges consideringboth objective statistical data available in the agency database of railroad bridges management and subjective data obtained form interviews with experts of the railway agency, which are used to anew uncertainty-based expected maintenance/repair costs including lifetime indirect costs. For reliable assessment of the life-cycle maintenance/repair costs, statistical analysis considering maintenance history data and survey data including the subjective judgments of railway experts on maintenance/management of railroad bridges, are performed to categorize critical maintenance items and associated expected costs and uncertainty-based deterioration models are developed. Finally, the formulation for simulation-based LCC analysis of railway bridges with uncertainty-based deterioration models are applied to the design-decision problem, which is to select an optimal bridge type having minimum Life-Cycle cost among various railway bridges types such as steel plate girder bridge, and prestressed concrete girder bridge in the basic design phase.

• 한국경영과학회지
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• 제20권2호
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• pp.39-60
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• 1995

In this paper, an integration of stochastic dynamic programming (SDP), integer goal programming (IGP) and analytic hierarchy process (AHP) is proposed to handle multiobjective-multicriteria sequential decision making problems under uncertainty inherent in R & D investment planning. SDP has its capability to handle problems which are sequential and stochastic. In the SDP model, the probabilities of the funding levels in any time period are generated using a subjective model which employs functional relationships among interrelated parameters, scenarios of future budget availability and subjective inputs elicited from a group of decision makers. The SDP model primarily yields an optimal investment planning policy considering the possibility that actual funding received may be less than anticipated one and thus the projects being selected under the anticipated budget would be interrupted. IGP is used to handle the multiobjective issues such as tradoff between economic benefit and technology accumulation level. Other managerial concerns related to the determination of the optimal project portifolio within each stage of the SDP model. including project selection, project scheduling and annual budget allocation are also determined by the IGP. AHP is proposed for generating scenario-based transformation probabilities under budgetary uncertainty and for quantifying the environmental risk to be considered.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.532-539
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• 1996

Existing assessment methodologies present a considerable problem because of fuzzy situation of deterioration mechanism of concrete bridges; namely, qualitative, subjective or inconsistent. This paper discusses current assessment methods in aspect of uncertainty. The expert system, COBDA, is developed for consistent and fast assessment of deteriorantion of concrete bridges. Briefly introduced in this paper are the structure of expert system and several methodologies for decision making of deterioration situation and providing repair option. COBDA is configured by PROLOG for logic approach and expert system shell based on Bayesian subjective probability. The methodologies are illustrated and discussed by comparison of condition assessment results in a case study.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.473-476
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• 2003

본 논문에서는 일반적인 건설공사에 있어서 불확실성 모델링을 사용한 체계적인 퍼지위험도 분석기법 및 절차를 제시하였다. 본 논문에서 제시한 기법 및 절차는 전문가의 경험과 주관적인 판단을 이용해서 공사관련 위험사건들의 확률을 결정함으로써 건설공사의 위험도분석을 보다 실제적으로 할 수 있으며 퍼지집합이론 및 퍼지수 개념을 사용한 불확실모델링은 불명확하고 변동이 많은 건설공사에 내재된 사건들을 제어하는 데 효과적이다. 이는 위험도 분석을 위한 객관적인 자료가 부족하고 또 이로 인해 불가피하게 전문가의 경험에 주관적인 자료에 의존하는 한국과 같은 나라에서는 본 연구에서 제시한 불확실 모델링 절차는 정량적인 위험도 분석을 가능하게 함으로써 위험도 관리를 위해서도 매우 유용하게 쓰일 수 있다.

• 여성건강간호학회지
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• 제13권4호
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• pp.290-298
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• 2007

Purpose: This study was to measure the quality of life(QOL) and to identify the related factors in gynecological cancer patients during chemotherapy. Method: The subjects of this study were the patients who had undergone a hysterectomy and were admitted for chemotherapy at S university hospital between November 2006 and April 2007. Data was collected from 106 gynecological cancer patients with the use of a structured questionnaire which measured the QOL(FACT-G), body image, the presence of anxiety & depression, uncertainty, and family support. The data was analyzed by the SPSS win 12.0 program. Results: The mean FACT-total score was 62.1$({\pm}16.7)$ (range; 26-107). Positive correlations were found between QOL and body image(r= .67, p= .00), and QOL and family support(r= .32, p= .00), whereas there were negative correlations between QOL and anxiety(r= -.54, p= .00), QOL and depression(r= -.70, p= .00), and QOL and uncertainty(r= -.59, p= .00). Fifty seven pre cent of the variance in subjective overall QOL can be explained by depression, body image, and uncertainty(Adj $R^2$= .57, F=47.00, p= .00). Conclusion: Our patients had a relatively low QOL score. Factors significantly affecting quality of life were depression, body image and uncertainty. Nursing interventions, therefore, should be focused on improving QOL in gynecological cancer patients during chemotherapy, particularly so in patients with depression, uncertainty or poor body image.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.85-110
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• 2008

Ground investigation data to be used as a basis for geotechnical analysis and foundation design are usually troubled with large uncertainty, due to natural variability and limited number of data. Statistical methods can be a rational tool for handling such uncertain ground data, in particular with a view to the selection of characteristic values for estimating ground design parameters used in design. The characteristic values of soil properties for use in geotechnical design have oftenly based on not only a subjective judgment but also engineer's past acumulated experience. This paper discussed some statistical methods which can handle such intrinsic ground uncertainty data with a case design in a rational manner.

• 여성건강간호학회지
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• 제26권1호
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• pp.72-83
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• 2020

Purpose: The purpose of this study was to investigate the effects of uncertainty and spousal support on infertility-related quality of life (QoL) in women undergoing assisted reproductive technologies. Methods: In this correlational survey study, 172 infertile women undergoing assisted reproductive technologies for infertility treatment at M hospital in Seoul participated. Data collection took place at the outpatient department of M hospital using a self-report questionnaire from July to August 2019. Data were analyzed using SPSS for Windows version 28.0. Results: The mean scores for uncertainty, spousal support, and infertility-related QoL were 28.35 (out of 50), 86.67 (out of 115), and 57.98 (out of 100), respectively. Infertility-related QoL was positively correlated with spousal support and negatively correlated with uncertainty. According to the regression analysis, infertility-related QoL was significantly affected by uncertainty, total number of assisted reproductive technology treatments, marriage duration, subjective health status, the financial burden of infertility testing, and the presence of a burdensome person. These variables had an explanatory power of 35.0% for infertility-related QoL. Conclusion: Uncertainty was an important factor influencing infertility-related QoL among women undergoing assisted reproductive technologies. It is necessary to develop and implement a nursing intervention program focused on reducing various forms of uncertainty during assisted reproductive procedures and to consider other factors affecting infertility-related QoL in the clinical setting.

• 한국지반공학회지:지반
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• 제3권2호
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• pp.17-28
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• 1987

본연구에서는 해양토질의 전단강도 산정에 대한 Cone관입시험의 신뇌도를 조사하였다. 사질토에 대하여는 내부마찰각의 불확정성을 조사하였으며, 불확정성에는 자료의 공간적 변화와 해석에 사용 되는 공식의 모텔오차 등이 있고, 그중 해석모텔의 오차가 가장 큰 불확정성이었다. 해석 방법마다 구한 내부마찰각이 서로 다르므로, 해석결과를 종합할 수 있는 주관적 견해개념(subjective opinion) 을 도입하였다. Cone관입시험을 이용하여 잡토지반에서 비배빙전단강도를 산정하기 위해서는 실훈시험이나 현장베인 시험으로 구한 전단강도와 Cone 저항력의 경험적인 관계를 이용하여야 한다. 비배수전단강도의 불확정성은 Cone 계수(Nk)의 자료 산포, Nk의 모델 오차, 이방성과 Cone 저항력의 공간적 변화 등에 기인하며, Nk의 자료산포가 가장 큰 불확정성이었다. Nk값의 산정에 이용되는 비교강도시험은 실내시험보다는 현장베인시험의 신뢰성이 더 큰 것으로 나타났다.